* Added new <code>absorber</code> type, as an alternative to PML, which simply provides a scalar conductivity gradient for cases where PML fails.

+

* Fixed bug which sometimes prevented dispersive materials from being used in PML regions.

+

* Some fixes to BLAS/LAPACK linking.

+

* Bug fixes in LDOS computation.

+

* Work around [http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54498 gcc bug #54498], which caused a spurious PML test failure with gcc 4.7 and 4.7.1; thanks to Brahmanand Jogai and Thorsten Alteholz for the bug reports.

+

+

==Meep 1.2==

+

<small>20 July 2012</small>

+

* Fixed to work with Guile version 2.x (older versions still work); requires libctl 3.2 or later.

* Meep's [[PML]] is now a true PML for arbitrary anisotropic, dispersive, and conducting media. (Now uses a slightly unconventional reformulation of PML described at [http://ab-initio.mit.edu/meep/pml-meep.pdf ab-initio.mit.edu/meep/pml-meep.pdf])

* Fix compilation failure with gcc 4.4 due to missing <code>cstdio</code> header (thanks to Linran Fan and Bin Shao for the bug reports).

+

* C++ interface: <code>volume</code> was renamed to <code>grid_volume</code> and <code>geometric_volume</code> was renamed to <code>volume</code>, to better reflect their respective roles.

+

* Added <code>accurate-fields-near-cylorigin?</code> option to have more accurate fields near the ''r''=0 origin for large ''m'' in cylindrical coordinates, at the expense of requiring a smaller Courant factor. (Default is <code>false</code>, corresponding to behavior in older Meep versions.)

+

* In 2d computational cells, added much more efficient support for <math>e^{ikz}</math> ''z''-dependence, enabled by new <code>special-kz?</code> input variable (default is <code>false</code> since it only works in 2d and is a little subtle for real fields).

+

* Includes preliminary new features to aid in computation of optical forces (both classical and quantum Casimir forces); further documentation pending more testing.

+

* Removed obsolete <code>doc</code> directory (all documentation is on the website these days).

+

* Small performance improvements in Lorentzian dispersion handling.

+

* Fix <code>configure</code> script failure when cross-compiling.

+

* Fix compilation failure with [[w:MPICH|MPICH]].

+

+

==Meep 1.0.3==

+

<small>5 June 2009</small>

+

+

* Allow <code>GUILE_CONFIG</code> environment variable to override location of <code>guile-config</code> program in <code>configure</code> script; this is useful when cross-compiling.

* Use new automake features to have less-verbose build output by default (you can build in verbose mode by <code>make V=1</code>), and running all test programs then reporting which ones failed instead of stopping at the first failure.

* New timestepping scheme for off-diagonal anisotropic epsilon and mu, based on technique by Werner and Cary <nowiki>[</nowiki> ''J. Comp. Phys.'' 226, 1085 (2007) <nowiki>]</nowiki>, that improves FDTD stability when anisotropy is present (such as when subpixel averaging is used on isotropic media).

* Anisotropic dispersive materials are now supported, although currently the dispersive part of the epsilon/mu tensor must be diagonal, via the new <code>sigma-diag</code> parameter of polarizability. (The corresponding C++ interface has also removed <code>delta_epsilon</code>.)

+

* The <code>delta-epsilon</code> parameter of polarizability has been removed; you should use <code>sigma</code> instead.

* In the Scheme interface, subpixel averaging is not used for user-specified material-function types; you only get subpixel averaging for the standard shapes (blocks, cylinders, etcetera).

+

* Haskell code-generation is no longer used, and <code>hsrc</code> directory is removed. Bitrotted and undocumented (hence unused) saturable-absorber feature has been removed, along with <code>energy-saturation</code> parameter of polarizability.

+

* Some bug-fixes to test programs that made them overly sensitive to roundoff errors and possibly fail depending on the compiler. (New <code>fields::round_time</code> and <code>meep-round-time</code> functions to round times to single-precision, useful for robust time comparisons.)

+

+

==Meep 0.20.4==

+

<small>17 March 2009</small>

+

+

* Bug fix in cylindrical code, which caused it to blow up in some circumstances for nonzero m.

* Support for user-specified permeability (mu). Renamed "<code>dielectric</code>" to "<code>medium</code>" in libctl interface, new "<code>mu</code>" property and new <code>output-bfield</code> and <code>output-mu</code> functions, and new "<code>Permeability</code>" and "<code>Bx</code>" etc. field types.

+

* Support for user-specified electric and/or magnetic conductivities. These are especially useful to add a desired dissipation loss (an imaginary part of &epsilon;/&mu;) in a narrow bandwidth, without messing around with Lorentzian dispersive materials.

* Added <code>synchronized-magnetic</code> step function to allow step functions to run with the electric and magnetic fields synchronized in time to second-order accuracy. See [[Synchronizing the magnetic and electric fields]].

+

* New PML implementation (UPML instead of split-field), should have lower reflection in many cases.

+

* User-specified PML profile and asymptotic reflection.

+

* Internally, all timestepping code is now handwritten (and much shorter) rather than old verbose Haskell-generated code; this should make it easier to add new features.

+

* Add support for non-integrated current sources, if the <code>is-integrated?</code> property of the current is set to false; this is now the default, to make handling of '''E''' and '''H''' sources more similar and intuitive.

+

* Work with HDF5 1.8 (which previously would not compile unless you manually set a preprocessor flag, due to API changes).

+

* Check for <code>ctl.h</code> in <code>/usr/include/ctl/ctl.h</code> (default in Fedora), and check for libctl in <code>/usr/share/libctl3</code> (default in Debian &amp; Ubuntu).

+

* Bug fix: fixed relative phase of '''E''' and '''H''' sources (which were off from one another by half a timestep); thanks to M. Megens for bug report.

+

* Bug fix: make sure h5 filenames have unique timestep for cases where &Delta;t is very small or very large.

+

+

==Meep 0.10.1==

+

<small>13 November 2007</small>

+

+

* Bug fix in <code>flux_in_box</code>, which accidentally returned the flux multiplied by the number of processors, instead of the flux.

* Fixed bug that caused <code>output-tot-pwr</code> to stop Meep with an error message; thanks to Vyacheslav Sokolov for the bug report.

+

* Make <code>at-every</code> step functions less susceptible to rounding errors; thanks to L. Le Guyader for the bug report.

+

* Fixed bug in dispersive media that wasted memory on parallel machines (the polarization memory was not parallelized); thanks to J. L. Silva for the bug report.

+

* Bug fix in <code>output-png+h5</code>, thanks to a report by Chad Husko.

+

* Fixed several deadlocks that could occur when the parallel Meep is used with a serial HDF5 library (we continue to recommend using the parallel HDF5 library with parallel Meep, however). Thanks in part to Lingling Tang for his bug report.

Meep 1.1.1

Meep 1.1

Meep's PML is now a true PML for arbitrary anisotropic, dispersive, and conducting media. (Now uses a slightly unconventional reformulation of PML described at ab-initio.mit.edu/meep/pml-meep.pdf)

Fixed bug which caused anisotropic non-diagonal μ to be unstable.

Fix compilation failure with gcc 4.4 due to missing cstdio header (thanks to Linran Fan and Bin Shao for the bug reports).

C++ interface: volume was renamed to grid_volume and geometric_volume was renamed to volume, to better reflect their respective roles.

Added accurate-fields-near-cylorigin? option to have more accurate fields near the r=0 origin for large m in cylindrical coordinates, at the expense of requiring a smaller Courant factor. (Default is false, corresponding to behavior in older Meep versions.)

In 2d computational cells, added much more efficient support for eikzz-dependence, enabled by new special-kz? input variable (default is false since it only works in 2d and is a little subtle for real fields).

Includes preliminary new features to aid in computation of optical forces (both classical and quantum Casimir forces); further documentation pending more testing.

Removed obsolete doc directory (all documentation is on the website these days).

Meep 1.0.3

Meep 1.0.2

2 June 2009

Correct superficial make check failure on 32-bit x86 machines with gcc 4.3.x, due to slight impact on floating-point rounding by automatic SSE/SSE2 vectorization; thanks to Silviu Popescu for the bug report.

Meep 1.0.1

28 May 2009

Enable correct operation and passed test suite when MEEP_SINGLE (single-precision) mode is enabled in meep.hpp; thanks to Seyoon Kim for the bug reports.

Use new automake features to have less-verbose build output by default (you can build in verbose mode by make V=1), and running all test programs then reporting which ones failed instead of stopping at the first failure.

Meep 1.0

28 March 2009

New timestepping scheme for off-diagonal anisotropic epsilon and mu, based on technique by Werner and Cary [ J. Comp. Phys. 226, 1085 (2007) ], that improves FDTD stability when anisotropy is present (such as when subpixel averaging is used on isotropic media).

Anisotropic dispersive materials are now supported, although currently the dispersive part of the epsilon/mu tensor must be diagonal, via the new sigma-diag parameter of polarizability. (The corresponding C++ interface has also removed delta_epsilon.)

The delta-epsilon parameter of polarizability has been removed; you should use sigma instead.

In the Scheme interface, subpixel averaging is not used for user-specified material-function types; you only get subpixel averaging for the standard shapes (blocks, cylinders, etcetera).

Haskell code-generation is no longer used, and hsrc directory is removed. Bitrotted and undocumented (hence unused) saturable-absorber feature has been removed, along with energy-saturation parameter of polarizability.

Some bug-fixes to test programs that made them overly sensitive to roundoff errors and possibly fail depending on the compiler. (New fields::round_time and meep-round-time functions to round times to single-precision, useful for robust time comparisons.)

Meep 0.20

19 July 2008

Support for user-specified permeability (mu). Renamed "dielectric" to "medium" in libctl interface, new "mu" property and new output-bfield and output-mu functions, and new "Permeability" and "Bx" etc. field types.

Support for user-specified electric and/or magnetic conductivities. These are especially useful to add a desired dissipation loss (an imaginary part of ε/μ) in a narrow bandwidth, without messing around with Lorentzian dispersive materials.

Fixed bug that disabled subpixel averaging for dimensions=1 (thanks to Mischa Megens for the bug report).

Fixed bug that caused output-tot-pwr to stop Meep with an error message; thanks to Vyacheslav Sokolov for the bug report.

Make at-every step functions less susceptible to rounding errors; thanks to L. Le Guyader for the bug report.

Fixed bug in dispersive media that wasted memory on parallel machines (the polarization memory was not parallelized); thanks to J. L. Silva for the bug report.

Bug fix in output-png+h5, thanks to a report by Chad Husko.

Fixed several deadlocks that could occur when the parallel Meep is used with a serial HDF5 library (we continue to recommend using the parallel HDF5 library with parallel Meep, however). Thanks in part to Lingling Tang for his bug report.

For maintainer-mode, improved detection of Haskell package names; thanks to Liang Huo for the bug report.

Meep 0.10

21 August 2006

eps-averaging? is now turned on by default (in libctl interface), using much-improved algorithm by Ardavan Farjadpour. This greatly improves accuracy, and also allows continuous tuning of geometric parameters. (See our upcoming paper in Optics Lett., with a preprint at Citing Meep.) New input variables subpixel-tol and subpixel-maxeval to control the accuracy of the subpixel averaging.

Support for χ(2) (Pockels) as well as χ(3) (Kerr) nonlinearities.

Symmetries no longer require the cell size to be an even number of pixels. Previously, Meep exited with an error in this case, whereas now it simply adds an extra pixel to the cell size as needed.

New with-prefix step function to allow you to use a different filename-prefix for selected outputs.

New feature for output-png: built-in shell variable $EPS that refers to the last-output epsilon .h5 file, which you can use to easily add dielectric contours/overlays to the field output image.